TCGA has historically relied on retrospectively collected biospecimens. These tissues were accrued by dozens of TSSs around the world through a series of subcontracts managed through the prime contractor at SAIC-Frederick. TSSs included clinical sites, academic institutions as well as commercial companies with biorepositories. Retrospective samples have been invaluable sources of tissue and clinical data, often including long term follow-up. However, the rigorous biospecimen quality, including amount of tissue needed (between 100-150mg), percent of tumor nuclei (at least 70%) and low amount of necrosis (less than 30%) has posed challenges, requiring TCGA to look also at prospective collections. The purpose of this project is to establish Tissue Source Site (TSS) networks capable of delivering clinically annotated biospecimens through either/both retrospective and prospective collections. The tissues and clinical data will be delivered to one of TCGA[unreadable]s Biospecimen Core Resource(s) (BCR) for storage, quality control, processing into molecular analytes, and other research efforts. Ultimately, the samples will be characterized for copy number variation, single nucleotide polymorphisms, epigenomic profiles, gene and miRNA expression and mutation analysis.